Most metal melting, furnaces are formed of a metallic shell having an inner refractory lining that separates and insulates the metallic shell from the molten metal contained within the furnace. The refractory linings are generally formed by refractory bricks that are stacked along the inner surface of the metallic shell. The depth of the bricks (i.e. the thickness of the refractory lining) varies depending upon the type of furnace and the type of molten metal to be contained therein.
In the steel making industry, to allow the tapping of molten steel or iron from the furnace, refractory components conventionally referred to as "taphole sleeves" are provided in the side of the furnace. A taphole sleeve is generally a cylindrical tube formed of a refractory material that has a passage or bore extending therethrough. The taphole sleeve is generally positioned within the furnace wall below the surface of the molten metal so that when the molten metal is tapped, impurities that usually float on the surface of the molten metal bath will not be removed through the taphole. The taphole sleeve thus extends through the furnace wall (i.e., through the metallic shell and the refractory lining).
Tapholes vary in size and length from furnace to furnace, and therefore are generally custom made for particular furnaces and applications. In addition, the orientation of a taphole in a furnace wall (i.e., the angle at which the taphole sleeve extends through the furnace wall) varies from one furnace to another. In this respect, in addition to providing a passage through the furnace wall, the taphole sleeve must be oriented to direct the molten metal along a specific path into a receptacle, such as a ladle or the like. In many operations, the impact point of the stream of molten metal within a receptacle must be carefully controlled. Thus, the orientation of the taphole sleeve in the furnace wall is very important.
Conventionally, taphole sleeves are positioned and held within a furnace wall within a block of a castable refractory material. Typically, the taphole sleeve is placed into its desired position and orientation, and a refractory castable material is cast or rammed around it to hold it in place. This casting procedure typically requires the use of forms so that the resulting cast block will have external, planar surfaces on and against which the refractory bricks forming the refractory lining may be stacked.
As will be appreciated, the positioning of a taphole sleeve in accordance with the foregoing procedure is labor-intensive, time-consuming and costly. Moreover, the refractory castable used to secure taphole sleeves typically does not have the strength and refractory characteristics possessed by pressed refractory bricks, and therefore may be more susceptible to failure.
The present invention overcomes these and other problems by providing a modular taphole sleeve assembly formed of pressed refractory components, wherein the orientation of the sleeve relative to the assembly is adjustable, and wherein the assembly has planar, rectilinear, peripheral surfaces on and against which refractory bricks may be stacked.